Winchester disc drives are used in computers to store increasingly large amounts of information. A typical Winchester disc drive is a system with a limited number of mechanical parts, including a spindle motor which mounts one or more discs for constant speed rotation, and an actuator carrying a transducer at one end and a voice coil motor at the other, and operable in response to commands to the voice coil motor to position the transducer over a selected track on a disc to read and write data.
As one of the most expensive elements of the disc drive, as well as one of the largest and most mechanically complex, many design efforts are intended to minimize the cost and ease of assembly of the spindle motor. This particular invention is especially directed to improving spindle motor design to incorporate means for centering the stator stack on the shaft so that it is properly aligned with the magnet supported on the hub rotating outside the stator. The hub then remains properly centered over the shaft and stator without the creation of any undesirable axial or radial torque, also the maximum rotational torque is established between stator and rotating hub.
A further problem intended to be addressed in the design would be to eliminate the need for adhesive bonding between the stator and the shaft on which it is mounted. A related problem which it is also desirable to address is to provide an effective electrical grounding path between the stator and the shaft,